Pharmacology and Toxicology Science and Policies

1. Pharmacology and ToxicologyScience and Policies Nursing and Chemical Policies Barbara Sattler, RN, DrPH, FAAN University of Maryland School of Nursing

2. Pharmacology is the scientific study of the origin, chemical nature, effects and use of drugs. Toxicology is the science that investigates the adverse effects of chemicals on health. Pharmacology vs. Toxicology

3. Pharmacology Dose refers to the amount of drug absorbed from an administration Toxicology Dose refers to the amount of chemical introduced into a biological system Dose

4. Pharmacology Administration of a drug can be one time, short or long-term. Toxicology Exposure is the actual contact that a person has with a chemical. It can also be one time, short or long-term. Administration

5. Pharmacology Graphically represents the relationship between doses of a drug and the response elicited. Toxicology Describes the relationship of the body’s response to different amounts of an agent such as a drug or toxin. Dose-Response Curve

10. Distribution, Metabolism, & Excretion Pharmacology and Toxicology (ADME) • Absorption is the amount of a substance that enters the body • Distribution: Organs/Tissues/Cells that are reached • Metabolism: Chemical Transformation /metabolites • Excretion: Elimination/Persistence

11. Pharmacology Routes of Administration: oral, IM, IV, inhalation, dermal, ocular, etc. Toxicology Routes of Entry: ingestion, inhalation, dermal absorption, ocular, etc Routes of Administration or Exposure

12. In pharmacology there are therapeutic responses to drugs (desirable) and side effects (undesirable). In toxicology only the negative health effects are of concern. Pharmacology vs. Toxicology

13. Pharmacology Potency refers to the relative amount of a drug required to produce the desired response. Toxicology The toxicity of a chemical refers to the relative amount it takes to elicit a toxic effect compared with other chemicals. Potency vs. Toxicity

14. Definition of Toxicity Toxicity refers to the ability of a chemical to damage an organ system, to disrupt a biochemical process, or to disturb an enzyme system.

15. Three Types of Effects Additive: the sum = the whole Antagonistic: one reduces the effect of the other Synergistic: one enhances the other’s effect

16. Cummulative exposures occur when multiple sources of one or more toxic chemical exist.For example, in a single day, we can be exposed to pesticides in our homes, workplaces, and outdoors, as well as from the food we eat.

17. Mixturesand Multiple Cummulative Exposures Little is known about the toxic effects of multiple hazardous chemicals.

18. Pharmacology Bio-monitoring is done for some drugs: For example: Clotting time is monitored for patients on coumadin. Actual drug levels are measured for some drugs. Toxicology Bio-monitoring is done for some toxic exposures such as blood lead levels or metabolites of chemicals (biomarkers). Biological Monitoring

19. Pharmacology Therapeutic Index is the relationship between a drug’s therapeutic effect and its adverse effects. Toxicology Threshold levels refers to the amount of a substance necessary to cause a response in the body. Index vs. Threshold

20. Pharmacology/Toxicology • The effects of drugs and hazardous chemicals can be immediate (acute), long-term (chronic), or can present after a latency period. • Drugs are taken voluntarily and often under the supervision of a licensed health care provider. • Hazardous chemical exposures are most often involuntary.

21. Host Factors Host factors must be considered for therapeutic drugs or hazardous chemicals. Factors such as age, genetics, weight, drugs that a person may be taking, pregnancy status, and others may impact the therapeutic or toxic effect of a drug or chemical.

22. Children's Special Vulnerabilities Children… • Are still developing and may have immature (more sensitive) biological systems. • Eat, breathe, and drink more per body weight than adults • Eat a smaller range of foods (greater dairy and fruit/fruit juices) • Behave in ways that may place them at greater risk for exposure • Hand-to-mouth exploration • Playing on the floor/ground

23. The regulatory process by which a drug comes to the market includes several stages of testing, including both animal and human testing. There is no requirement for pre-market testing of chemical products that are not foods, cosmetics, or pesticides. No original testing is required. Regulatory Processes:Pre-market testing

24. Drugs Grateful Med (PubMed) OSHA: http://www.osha.gov/dts/osta/otm/otm_vi/otm_vi_2.html NIOSH: http://www.cdc.gov/niosh/docs/2004-165/ PDR Poison Control Centers Hazardous Chemicals NLM Toxnet: http://toxnet.nlm.nih.gov/ ATSDR Toxfaqs: http://www.atsdr.cdc.gov/toxfaq.html TRI Data: www.scorecard.org HCWH: www.noharm.org OSHA: http://www.osha.gov/dts/osta/otm/otm_vi/otm_vi_2.html Toxicology Resources

25. New Evidence of Exposures • CDC “Body Burden” studies (NHANES) • The “Egg” Study • EWG “Cord Study” • Nursing Survey of workplace chemical exposures

26. If chemicals act like drugs, including causing physiologic changes (even at very low levels), shouldn’t they be regulated like drugs?

27. How can we exert our leadership in this emerging arena ?